Hoisting sling with bridge fixtures



March 3, 1970 NVENTORS AMM United States Patent 3,498,664 HOISTING SLING WITH BRIDGE FIXTURES Carl A. Damm, Bucks County, William J. Halpern, Philadelphia, and John R. Hess, Oreland, Pa., assignors to the United States of America as represented by the Secretary of the Navy Filed Nov. 29, 1967, Ser. No. 686,440 Int. Cl. B66c 1/12; A62b 35/00; A65j 1/22 US. Cl. 29474 7 Claims ABSTRACT OF THE DISCLOSURE A hoisting sling for hoisting stores having peripherally mounted conduits or objects including an encircling,

' flexible, perforated strap and a pair of underlying bridge fixtures removably connected to the strap adjacent the store and in positions on opposite sides of a peripheral object to be protected from loading by the strap. Each fixture includes a specially shaped flexible, resilient bridge pad, an anchor fitting, a bifurcated clip and a removable detent pin for connecting the clip, the anchor fitting and the intervening pad to the strap.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the pay ment of any royalties thereon or therefor.

BACKGROUND OF INVENTION The handling and hoisting of stores such as missiles including peripherally mounted antenna fairings, conduits or other objects which may be damaged by peripheral loading cannot be easily accomplished with known hoisting apparatus in situations where the store is not provided with hoist fittings. For example, the hoisting configurations which are disclosed by C. A. Damm in U.S. Patents Nos. 3,083,993 and 3,086,809, issued respectively Apr. 2, 1963, and Apr. 23, 1963, include an encircling perforated metal strap which is tightly wrapped about the store. These configurations would, if used, crush or damage peripherally mounted fittings or conduits and, thereby, impair the utility of the store.

BRIEF SUMMARY OF INVENTION It is a general purpose of this invention to provide an inexpensively manufactured and easily used hoisting sling configuration which includes a strap which tightly engages the store periphery and yet is also spaced from selected objects mounted on the store periphery. Briefly, the general purpose and objects of the invention which may hereinafter become more apparent are accomplished by providing a store encircling strap and a pair of bridge fixtures which are readily attachable thereto. More particularly, the fixtures each include a resilient flexible bridge pad having a triangular cross section taken along the extent of the strap and having a pair of obliquely aligned planar surfaces separated by a groove for conforming to the various peripheries of a range of variously diametered stores and having its obverse side configured for receiving an anchor fitting which is adapted for connection to the perforated strap and to which the pad is removably connected. By appropriately spacing the bridge fixtures along the perforated strap, the overlying encircling strap is positioned above the peripherally located object which cannot withstand substantial peripheral loading.

BRIEF DESCRIPTION OF DRAWING FIG. 1 represents an end view in cross section of a cable hoist configuration according to the invention as used with a store having a peripherally located object;

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FIG. 2 is an enlarged fragmentary view of a portion of the apparatus of FIG. 1;

FIG. 3 represents an exploded isometric view of a bridge fixture of the apparatus of FIG. 2; and

FIG. 4 represents a view in elevation of an unfiexed bridge pad of the bridge fixture of FIG. 3.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to FIG. 1, the hoisting configuration which is generally designated as 10 is adapted for hoisting a store 11 having a peripherally mounted antenna fairing, conduit or other object generally represented by a tube 12. The configuration 10 includes a girth for the store 11 such as an encircling perforated strap 13 made of a flexible strip of metal and having its ends connected together by a latch 14 preferably of the type more particularly described in the above-noted Patent 3,086,809 to Damm. In order to hoist the store 11, the ends of a pair of hoisting cables .15 are threaded through anchor fittings 16 and are connected to the latch 14 as is more particularly shown in the above-noted Patent 3,083,993 to Damm. It is preferred that the strap 13 tightly encircle the store periphery in order to prevent rolling of the store 11 therewithin and in order to distribute the compressive strap and cable load substantially uniformly about the store periphery to protect the store 11 from damage.

In order that the strap 13 not crush or damage the tube 12, the apparatus 10 includes, as is more clearly shown in FIG. 2, a pair of bridge fixtures generally designated as 20 which are connected to the strap 13 and are arranged to engage the store periphery on opposite sides of the tube 12. Referring to the exploded view of FIG. 3, each of the strap supporting fixtures 20 includes a bridge pad 21 having a generally triangular cross section taken along the extent of the strap 13, the shortest side 21a of the pad 21 confronting the tube 12. Each pad 21 has on one side an obliquely arranged pair of planar, storeengaging surfaces 21b and 210 which are separated by a rectangular groove 21d transversely extending across the pad 21. The groove 21d has a width which is narrow compared with the extent of the surfaces 21b and 210 so that the loading imposed through the fixture 20 by the encircling strap 13 is distributed over a larger area of the store periphery. The relatively acutely inclined obverse side of the pad has a pair of longitudinally inclined, obliquely arranged bearing surfaces 21:: and 21 which extend from a centrally located transverse ridge 2.1g, which terminate at the ends of the pad 21 adjacent spaced retaining ridges 21h and 21 projecting therefrom and which form a seat for an anchor fitting having a concavely curved abutting surface 22a. The fitting 22 is laterally flanked by a pair of projections 22b which have coaxially aligned apertures 22c and are spaced apart for receiving therebetween the perforated strap 13. The fitting 22 also has a centrally located, slotted cylindrical boss portion 22d which has apertures 22c coaxially aligned with the apertures 22c and which protrudes through a perforation in the strap 13. In assembling the fixture 20, the pad 21 is loosely attached to the strap engaged anchor fitting 22 by a bifurcated clip 23 of sheet metal whose narrowed medial portion 23a is loosely received within the groove 21d of the bridge pad 21 and whose projections 23b are arranged on respective sides of the fitting 22 adjacent the projections 22b and have apertures 23c arranged in registry with the apertures 22c and 22e. A detent pin 24 is removably inserted above the strap 13 through the coaxially registering apertures 0f the clip 23 and the anchor fitting 22 so that prior to tightening the strap 13 about the store 11 the pad 21 is loosely entrapped for six degrees of limited freedom between the clip 23 and the fitting 22 and is thereby loosely connected to the strap 13.

It is preferred that the pad be flexible and resilient in order that the curved surface 22a of the fitting 22 can compress or flex the pad 21 to cause the surfaces 21b and 210 to assume a contiguous, nonslipping engagement of the periphery of the store 11 upon tightening of the encircling perforated strap 13 by manipulation of the latch 14. In this manner the pad 21 acts like a spring in compression, tends to protect the store finish, and does not slip over the periphery of the store 11 to damage the tube 12.

As shown in FIGS. 3 and 4, the surfaces 21b and 210 of the unflexed pad 21 are not coplanar, the surface 210 extending obliquely away from the extension of the surface 21b and away from the obverse side of the pad 21. The ridge 21g facilitates flexure of the pad 21 to attain nonslipping engagement of the store 11 because the obverse surface 22a of the fitting 22 is curved to engage the pad 21 both at the ridge 21g and at its ends adjacent the ridges 21h and 21 The rectangular groove 21d, which extends in the same direction as the bisector of the angle defined by the surfaces 21:: and 21 has bottom corners which along with the surfaces 21c and 21 define the narrowed portions P of the pad 21. Therefore, when the fitting 22 forces the ridge 215 towards the store 11, pad flexure at the portions P is permitted, the bottom of the groove 21d tending to become convexly curved. The spring action of the pad 21 is thereby enhanced, and the flexible pad 21 can readily be flexed by the anchor fitting 22 for contiguous nonslipping engagement of the peripheries of a variety .of variously diametered stores such as 11. The retaining ridges 21h and 21 keep the anchor fitting 22 from sliding otf the bearing surfaces 21e and 21 of the pad 21.

A suitable material for the pad 21 is a polycarbonate plastic such as Lexan made by the General Electric Company, which plastic is flexible, resilient, tough and impact resistant and has good notch sensitivity and good compressive strength. Such plastic pads may easily be fabricated as by molding, extruding, or other processes.

The obverse side of the pad 21 including the surfaces 21e and 21 generally defines along with the store-engaging side of the pad 21 including the surfaces 21b and 210 a relatively acute angle A, shown in FIG. 4, so that the upper retaining ridges 21 of confronting pads 21 are spaced from the store periphery a sufficient distance to cause the encircling strap 13 to span the tube 12 in spaced relation thereto. Varying degrees of strap clearance are permitted by appropriate spacing of the fixtures 20 along the strap 13 prior to tightening same about the store 11. It is prefererd that the acute angle A be such that the portion of the strap 13 extending from the boss portion 22d of the anchor fitting 22 towards engagement of the store periphery is not substantially bent over the lower ridge 21h and such that the portion of the strap 13 extending toward the confronting fixture 20 is bent over the upper ridge 21j. The tube confronting side 21a of the pad is chamfered so that the surface thereof is inclined from perpendicular alignment with the store periphery. As the strap 13 is tightened about the store, a bending moment is created tending to rotate the upper ridge 21 toward the tube 12. It is preferred that the area of the surface 21c be less than the area of the surface 211: so that a greater resultant force tends to be applied to the store through the surface 210. Thereby, pad flexure is further enhanced, and any tendency of the pad slippage is directed away from the tube 12.

As a practical matter, the pad 21 itself could be equipped with tangs arranged for connection as by the detent pin 24 to the anchor fitting 22. However, it is preferred that the bifurcated clip 23 be utilized for enabling the above-indicated loose connection of the pad 21 to the anchor fitting 22 and the strap 13 in order to assure that the fitting 22 can flex the pad 21 without interference t 5. 1 the surfaces 21b and 210 to contiguously engage the store periphery when the strap 13 is tightened. The preferred spaced-apart position of the medial portion 23a of the clip 23 relative to the groove 21d at a time when the fitting 22 is moved into engagement with the ridge 21g is shown in dotted lines in FIG. 4. The loose connection is further beneficial in that manufacturing tolerances for the components of the fixture 20 may be substantially less critical.

It is contemplated that the bridge fixtures 20 readily may be used in hoisting configurations other than that shown in FIG. 1 such, for example, as the configuration shown in the Patent 3,086,809 to Damm. It is also contemplated that a pair of the bridge fixtures 20 may also be used in combination with the encircling, tightened strap 13 to prevent stowed stores of circular cross section such as 11 from rolling. In this application, the fixtures 20 are peripherally located adjacent the bottom of the store 11 with the anchor fittings 22 or the strap covered ridges 21 resting on the store supporting surface.

It should be understood, of course, that the foregoing disclosure relates only to a preferred embodiment of the invention and that numerous modifications or alterations may be made.

We claim:

1. In a cable hoisting configuration for a store having a peripherally mounted object; apparatus comprising:

flexible strap means for tightly encircling the store in engagement with the store periphery;

a pair of bridge pads made of resilient material and each having a generally triangular configuration including a store periphery engaging side, an obverse side acutely inclined relative thereto and an object confronting side extending therebetween; and

the extent of said object confronting side of each of said pads is shorter than the extent of said obverse side thereof;

means for attaching said pads to said strap adjacent the store and on respective sides of the peripherally mounted object for spacing said strap from the object, said means for attaching having a pair of anchor fittings each formed for connection to the store adjacent side of said strap; and

said obverse side of each said bridge pad terminating at its ends in a pair of retaining ridges for receiving therebetween a respective said anchor fitting in engagement therewith.

2. Apparatus according to claim 1 wherein:

said periphery engaging side of each of said pads includes formed therein intermediate its ends a transversely extending groove, the segments of said periphery on either side of said groove being normally obliquely arranged to define a segmented, generally concave periphery engaging side.

3. Apparatus according to claim 2 wherein:

the pad engaging side of each said fitting is concavely curved along said extent of said obverse side of said bridge pad; and

said obverse side of each said pad includes a pair of obliquely arranged planar surfaces which intersect obversely of said groove to form a projecting ridge engageable by said respective fitting.

4. Apparatus according to claim 3 wherein:

said groove in each said pad is defined by sides extending inwardly to a planar bottom surface thereof.

5. Apparatus according to claim 4 further comprising:

a pair of bifurcated clips each having a medial portion received within said groove of a respective said pad, the bifurcated portions thereof projecting in spaced relation for receiving therebetween said paid and said respective anchor fitting; and

a pair of means for connecting said clips to respective said anchor fittings.

6. Apparatus according to claim 5 wherein:

said strap means includes a flexible strap having a plurality of perforations formed therein:

each said anchor fitting includes coaxially apertured each of said medial portions of said clips is normally projections spaced apart for receiving therebetween spaced from the boundaries of the respective said said strap and includes a boss portion having a cogroove. aKially aligned aperture extending therethrough and References Cited receivable 'withina respective said strap perforation; 5 UNITED STATES PATENTS said bifurcated portions of each said clip having formed therethrough apertures coaxially aligned with those of i; aid lat s f ares ect've said fitt' ;a d t 0 e S P 6 P 1 mg n 3,083,993 4/1963 Damm 294-75 said apparatus further includes a pair of removable pins each threaded through respective apertures of 10 HARVEY C HORNSBY Primary Examiner said clip and said anchor fitting for connecting each I said clip with said respective fitting, said respective CL pad being held therebetween. 243 351 7. Apparatus according to claim 6 wherein: 

